There is so much falsehood in this statement I don't even know where to start. Obviously Lanza was a troubled person who had no intention of carrying out any "gangster fantasy". Gangsters don't kill themselves after shooting 20 kids. There is no correlation there. As for your mental disorder theory, different cultures place importance on different aspects of life. However, something like Body Dysmorphic Disorder (for example) is the same for anyone no matter what part of your body you feel is not in accordance with the social norm. Depression, ADD, or psychosis to name a few, all have the same root causes.
---------- Post added 2012-12-18 at 11:31 PM ----------
It's relevant because tragedy will always occur no matter how much you try to contain it.